1,3-Dioxolane-4-methanols are used as an intermediate of medicines, agricultural chemicals, etc. and the following processes for their preparation are known: (i) A process for their preparation is by reacting glycerin and an acetonide reagent (Synth. Commun., 22, 2653(1992), (ii) a process for their preparation from mannitol (Biochem. Prep., 2, 31(1952)), (iii) a process for their preparation from an ascorbic acid (J. Am. Chem. Soc., 102, 6304(1980), (iv) a process for their preparation from serine (Japanese Patent Publication B No. 6-62492), (v) an optical resolution of them by using an enzyme (J. Chem. Soc., Perkin Trans. I 23, 3459(1994) and so on.
These processes, however, have industrially following disadvantages:
According to the process for their preparation by reacting glycerin with an acetonide reagent of (i), a mixture of a compound acetalized between positions 1 and 2 and a compound acetalized between positions 1 and 3 is produced and it is hardly difficult to separate each compound from the mixture. According to the method of (ii), because a chemically equivalent amount of lead tetraacetate or sodium hyperiodic acid is used in case of cleavage of 1,2-diol compounds, it takes high costs and in case of preparing an optical isomer, only a (S)-form is obtained because only D-mannitol is present in nature. According to the process from L-ascorbic acid or D-isoascorbic acid of (iii), because a chemically equivalent amount of lead tetraacetate or sodium periodic acid is used, it takes high costs like in case of (ii). According to the method from serine of (iv), in case of preparing an optical isomer, only a (R)-form is obtained because only a (L)-form is present in nature as in case of (ii) and furthermore, in the reduction of the carboxylic acid, the reagent is difficult to deal with in mass production, such as lithium aluminum hydride, must be used. According to the process by the biochemically optical resolution method of (v), purity of one of optical isomers is high, but purity of the other is low, and in some cases, in order to separate an optically active alcohol and an optically active ester which are prepared from a racemic alcohol, separation by column chromatography is necessary and therefore, it is not suitable for mass production. Furthermore, all the processes mentioned above contain many steps and are not practical. Therefore, a more efficient process for preparation of a 1,3-dioxolane-4-methanols was desired.